Add a navigation panel for all block levels (similar to folding all leaf levels)

[ghost]

I often use text editors to edit long text files and the files has many blocks.
When I want to overview outline of the document, I need to use folding multi levels many times. It's not convenient.
If there's as navigation panel which content is similar to folding all leaf levels (or similar to navigation panel of offical word and libre writer), so it can overview more speedly and exactly.

I try to research and use many text editors but no one has the nagivation feature.

Also I don't want to use word processing such as offical word, libreoffice writer because they are so complicated, can not fast view file content. And text files are easy to backup and almost no risk of binary storages.

[zufuliu]

Duplicate of #253. (just click the toggle folds button) toggle fold for default levels (top 2 or 3 levels for most file) can be used show quick outline:

[ghost]

I know the features of the software. But it did not work well in some use cases:

1. Each block level-1 has different deep of levels. In the moment, to show outline, I need hide all leaf blocks. With navigation panel, always only show outline not content of leaf block.
2. When I want to browse of several blocks, I need to repeat steps: fold all to view outline and find out then unfold related blocks. With navigation, I always to see outlines and only click the target blocks to view content of the blocks.

Basically, I refer features of navigation of office word and libre writer. It helps to speedly view, arrange and edit the documents.

I realy like the indent & folding features of notepad2 that can apply for normal text files. It will be perfect when they combine with navigation feature.